Despite the many advances that have been made in the design of absorbent products such as diapers, incontinent products and sanitary napkins, there is a constant need for improved products that will offer the user greater security. Ways to enhance the absorbent capacity of such products have been found and widely utilized, for example, the inclusion of superabsorbent materials in product design. However, despite increased absorbent capacity, tests show that a surprisingly high proportion of such products still fail, i.e., the wearer experiences leakage and staining. In large part, such failure is due to the stress imposed upon the product during use. A sanitary napkin, for example, is subjected to significant distortional forces by the wearer's body movements. These forces can tend to compress the napkin laterally, causing it to rope or twist and thereby present a smaller area for fluid pick-up. Although this problem has been addressed in the art, there remains a need for new product designs that will successfully alleviate such distortion problems but that are also easily manufactured so that cost-effective products can be offered to consumers.
A number of patents have published disclosing sanitary napkins having an absorbent batt folded in a particular configuration.
U.S. Pat. No. 4,576,596 to Jackson et al. discloses a napkin in which an absorbent batt is folded on itself at least on each longitudinal axis with the fold being maintained by fusing areas of the adjacent layers over the batt near the folded edge.
U.K. Patent Application GB 2,124,499A discloses a sanitary napkin with an absorbent batt folded along the longitudinal edges to provide a cavity in the bottom portion of the napkin.
U.S. Pat. No. 3,699,966 to Chapuis discloses a sanitary napkin comprising alternate layers of hydrophilic and hydrophobic material, with the edges of the hydrophilic material folded inward to define a channel extending through the middle of one side of the napkin.
Other patents disclosing napkins containing an absorbent batt folded in a "C-fold" configuration are U.S. Pat. No. 3,667,468 to Nystrand et al., U.S. Pat. No. 3,954,107 to Chesky et al., and U.S. Pat. No. 3,364,931 to Hirsch.